The Role of DNA Binding in Transcription Activation by Estrogen Receptor

During the course of this study we created a superactive estrogen receptor by inserting of two copies of a well defined, synthetic 18 amino acid amphipathic helix into the hinge region of the Xenopus estrogen receptor (XER). The resulting mutant, XER/2AH, provides us with a useful tool to study the mechanisms of gene activation by estrogen. XER/2AH exhibited 2-3 fold increased hormone-dependent transcription. Using a minimal promoter containing two copies of the estrogen response element (ERE) linked to a TATA box, it exhibited a 10 fold increase in hormone-independent constitutive transcription activity compared to that of the wild-type XER. The hormone binding properties and protein expression levels of both the wild-type XER and the XER/2AH mutant are similar. Surprisingly, unliganded XER/2AH exhibited a striking 15-20 fold increase in DNA binding affinity over the wild-type XER. We also obtained the first evidence in vertebrates that binding to EREs by estrogen receptor is estrogen-dependent.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Xing, Hong

Contributors dc:contributor

• Shapiro, David J.

• Biology, Molecular

Identifier

(UMI)AAI9411830

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/72364